1. Field of the Invention
The present invention relates generally to the field of skateboard wheels and more specifically to a multi-element skateboard wheel having at least two different hardness surfaces including a softer center exterior surface and a harder side exterior surface.
2. Background Art
A skateboarder generally comes to a stop by either dragging a foot on the ground or by lowering the tail of the board to the ground and dragging the wood of the tail portion of the board on the riding surface.
Skateboard wheels have a wide surface engaging the ground. Skateboarders do not use round or parabolic wheels. The flat section of a skateboard wheel is anywhere from ⅜″ to over 2″ in width depending on the type of skating the individual prefers.
Thinner wheels are usually made of harder urethanes for skateboarders that like to do a lot of sliding tricks. They prefer a smaller footprint and harder urethane so that they can turn their boards sideways and slide with the board perpendicular to their momentum. This is a very popular trick called a “power slide”.
Fatter wheels are made with softer urethane for a smoother ride and more control, used by recreational skateboarders that do a type of skateboarding referred to as carving, where the skateboarders make subtle turns back and forth with their skateboard to propel themselves forward without placing their foot on the ground. Other types of skateboarding done on these wider wheels would be downhill racing and slalom racing where high speeds are attained and control is important to safety and success.
Softer wheels are slower but give more control because of a higher coefficient of friction. Hard wheels are fast but lack control because of a lower coefficient of friction.
Skateboarders are forced to compromise between speed and control. Giving the skateboarder a dual surface would eliminate the compromise. A design having both hard and soft urethanes in constant contact with the riding surface would give the rider the benefits of both.
It is important to have the harder urethane on the outside because of the tricks today's skateboarders are doing. When a skateboarder does “power slide”, he turns his board sideways with this toe facing forward in the direction he is moving and puts his weight on the heels of his foot and the backside of the board. This lifts or minimizes the pressure and contact of the leading edges of the wheels and allows the skateboarder to slide on the trailing edges. If a skateboarder were to perform this trick on dual durometer wheels, the pressure would be transferred to the trailing outer edge of the wheel which is constructed with the harder urethane with the lower coefficient of friction, allowing the skater to enjoy a slide as if he were on a single urethane wheel of harder durometer and lower friction.
Another favorite trick of the skateboarder is called the grind. This occurs when a skateboarder hops up onto a curb or rail and slides on the trucks of the skateboard in between the wheels. While performing this trick it is not uncommon for the skateboarder to slide on the truck and the inside wall of the wheel. This is done to help stabilize the rider while sliding and is referred to as locking in. The problem that exists with a high coefficient of friction wheel is that it may bite or stick to the surface the skateboarder is grinding. When this happens, the trick comes to an abrupt end throwing the rider from the board. This is another reason for having a low friction surface on the outside.